A multidisciplinary Center Grant is proposed to study the following areas: The afferent transmitter substance, effects of auditory deprivation on central-auditory nervous system development, ultra-audiometric studies of people with sensorineural losses in the traditional range but good hearing in the range from 8 to 18 kHz, auditory function in dyslexic children with auditory-perceptual disorders, dichotic listening and dichoptic viewing in normals and in patients with brain injuries, neurobehavioral and sensory studies of Vietnam veterans who suffered discrete head wounds, and studies of temporal-order judgment. Many of these studies are related to a "Special Test Development Unit" which is set up to clinically evaluate patients and to study human electrophysiology with special attention to the binaural-interaction response in auditory brain stem and middle-response areas.